The only appliances you need in your aquaponics system are a water pump to circulate water and an air pump to keep up the levels of dissolved oxygen. Ill discuss electrical pumps, since most folks have access to electricity, whether delivered by the power company or generated at home in some manner.
The water in your system should circulate completely once an hour. So if I have 200 gallons in my system, you might think a 200 gallon per hour (gph) pump is enough, right? Unfortunately, the flow rating on the box of a pump assumes there are no significant friction losses in the pipes and the water is only being pumped 1-2 feet up hill. Since I have 200+ gallons in this 365 Aquaponics system, Id want at least a 500 gph pump. Ive used 800 and 1000 gph pumps, which gives me plenty of power to overcome piping loss, intentional throttling, and bio-fouling (e.g., leaves and algae gumming up the works).
Most systems Ive seen use plastic pipe or tubing to carry water from the pump to the grow beds and tanks. But these tend to be expensive and/or complicated. As someone trained in the physics of fluid flows, it hurts my soul to see right angles in water pipes. Right angles create friction losses and invite blockage.
Turns out there are all kinds of manifolds with valves designed for garden hose. You can buy them at your local hardware store. And theyre cheap, because tens of millions of people buy them. So far, so good. Regular garden hose, however, isnt safe for drinking water due to the amount of lead it can leach into the water. Call me silly, but I dont like leaching lead into the water my fish drink and breathe. So I use special garden hose that is specifically designed for drinking water. If your local hardware store doesnt have it in stock, you can special order it, or order it online. Its not much more expensive than the stuff that leaches lead, and you can usually get it shipped for free if you shop around.
Draping the hose between the pump and grow bed is trivial for the growbeds on the same side as the sump. But its a bit more complex for the beds opposite the sump. Below is how I drape the hose, to ensure I dont kink the hose, dont block access to the garden, and put the hose opposite the end of the grow bed that drains into the sump or fish tank. Here is a video clip showing the water pump and hose installation.
Timers - If you have functioning bell siphons, you can leave the water pump running continuously. But there are reasons to have a simple timer to turn the water pump off and on:
Stopping water flow at night. You may do this because its cold weather, and you want to conserve thermal energy rather that spending energy to "cool" your water by circulating it during the dark nights. Or you might just want to keep it quiet for your neighbors. Since I turn my pumps off at night, I have drilled a small hole in the standpipe of my bell siphon so any excess water remaining in the grow beds can drain when power goes off for the night.
You dont want to deal with bell siphons. In this case, you can set the timer to turn on for 15 minutes every so often (say once an hour). As long as you have a standpipe with a small hole at the bottom, your beds will fill while the pump is on, then slowly drain when the pump is turned off.
Even with functioning bell siphons, you can throttle back on power requirements by turning the power off intermittently. This can be particularly important if you have an extended power outage, and are trying to maintain your system off a small solar array.
There are any number of timer systems out there, but I believe a simple timer like the one pictured above will take care of most needs for an aquaponics system.
Do all of us chicken mamas think our chickens are the best, smartest, and prettiest chickens ever born? Love must be blind because we really like our chickens a lot.
And our girls even have different colored eyes! Ours must be eggstra-special (okay, Ill stop).
But seriously, they have been out in their coop now for two weeks and everything has been going extremely well. No casualties, and they seem very happy.
Todd also finished the watering system in the chicken coop.
They can access their water outside under the coop.......
....or inside.
It holds a little over 2 and a half gallons of water, here is where we fill it. We hope to hook it up to our future rain barrel system one day.
It took them just a few days to learn how to drink from it. Several times a day, Todd would hold each one and put their beaks up to the chicken nipple, but only when we removed their plastic watering bowl did they finally figure it out.
Two days ago, they started going into their coop at nighttime on their own. Up until then, we had to pick up each one and put them in the coop. That was making me extremely frustrated because they would not go willingly and it would take the girls twenty minutes each night to get them in. It was mad chicken/children chaos every night at bedtime. The neighbor kids would even get in on it, too. Needless to say, were VERY glad that instinct finally kicked in.
If only we could convince the kids to go to bed on their own........
This post has been shared at: The Homestead Barn Hop, The HomeAcre Hop, The Backyard Farming Connection Hop, Simple Saturdays Blog Hop
floating raft (plants floating with their roots in a constant stream of water)
media-based growbeds (plants growing in some sort of rock/sand/gravel/beads)
Media-based systems are recommended for home hydroponicists because they are simpler and more reliable. Media-based systems are also referred to as flood and drain. The idea is you flood the growbed with the fish water (delivering nutrients and, um, water), then let it drain out (bathing the roots in air/oxygen).
Of the various ways to flood/drain a media-based growbed, the one that is easiest on the checkbook is a bell siphon. All a bell siphon needs are simple plumbing bits available at any hardware store. Oh, and a small pump. I loved the way the folks at EcoFilms explain it in their post about How an Aquaponics System Works:
"If the pump is the heart of an aquaponics system, then the auto-siphon are its lungs. A vital part of kit. Remember when you were a little kid and the teacher told you about the regular flooding of the Nile river and how fertile the Nile delta was to early farmers. Well think of the auto siphon as a kind of similar concept. Its main purpose is to flood the grow bed drawing rich oxygen into the depths of the trough, oxygenating the plant roots and turbo charging the bacteria to do their thing."
Below is EcoFilms animation of how a bell siphon works. [The red button toggles the animation on and off.]
A real-life system takes many times longer to fill than the time to drain (my initial prototype system with a single growbed took 10 minutes to fill and 1 minute to drain, ignoring the dribbly parts at the beginning and end of the siphon). I found the growbed in my system only needs 10 gallons to fill the spaces between the rocks, so the change in the level of the water in the fish tank is only 2-3 inches, about 10%.
Basically, when water reaches the top of the siphon, water quickly drains out of the grow bed, sucking air down around the roots and oxygenating everything. You can have a small pump running continuously, rather than a big pump turning on for only a few minutes once an hour or so. Since the pump is on continuously, the water in the total system is also cycling continuously, which my fish and plants love.
I didnt invent the bell siphon, but I have developed a design that doesnt require solvents, a design that can be manufactured with just plumbing bits and a mitre saw.
Ill show the bell siphon working in tomorrows post about the coanda discharge - for today the video just covers the parts and assembly of the bell siphon.
Most of you know that the domes frame is up, but heres the next video in the series about what will be hiding under the floor.
I had too much video to cram into 5 or 6 minutes so you get a double-feature today!
Well start with the sump tank thats located in the center of the dome area. Plastic tanks cant be buried directly in dirt since they expand and contract with temperature change and the weight of the dirt will eventually crush them. I surrounded the entire tank with scrap 2 by 4s and built a brick wall around it. When the well was completed, the goal was to simply lift the tank out, remove the boards and set the tank back in the well, resulting in a space between the tank and the well wall.
I didnt realize that the tank was slightly tapered so the bottom was larger than the top - the tank was trapped inside the well! If you watch carefully, you can see the entire well lift slightly with the tank. Some extra pondering was required
I decided to slide each board out one at a time until enough were removed to loosen the tank. I drilled part-way through the board, inserted a bolt, wrapped a strap around it, and lifted the board until it hit against the rim of the tank. Then cut the section of board off and repeated the process until the board came out. This was a few hours wasted, but it worked!
There is a larger sump tank that is located in the shed area that also needed a well built around it. This is a cone bottom tank so I tightly strapped some 2 by 4s as legs to it to keep it level, then set the rest of the spacer boards around it. After leveling out the area, I set some cement blocks on the ground to act as a footing for the brick work. When it was complete, a perfectly round well was surrounding the tank and we were able to pull the tank out with the excavator.
This is the baby brother excavator compared to the one that dug the foundation hole. With a slightly smaller bucket, it was able to place the dirt back into the bottom half of the hole. Bruce, the operator, was very careful and didnt hit a single block off the wall! When the area was roughly level, he tamped the dirt into place to help prevent future settling.
While Bruce graded around the exterior of the foundation, I set the tubing for the thermal mass. There are 5 equal length perforated pipes that connect to a central manifold which will eventually be connected to a heating system. The tubing zigzags around the floor to help spread the heat evenly throughout the dome. The exhaust for each tube then vents to a different area in the dome.
Six inches of stone was placed around the tubing. This is partly to protect the tubing from larger rocks, and partly to allow some more air flow for heat distribution into the thermal mass floor.
Earlier in the project, I didnt have time to set the anchor bolts in the foundation wall. To make sure they were placed in the correct locations, I first cut all the treated lumber sill plates to their correct lengths and labeled them. I then drilled a hole for the anchor bolt into each plate, roughly in the center of a one of the block cavities.
The entire cavity didnt need to be filled with concrete so I filled them half way with stone first. It was a nice day so I got a helper. Her job was to vibrate the air pockets out of the concrete as I shoveled it into the cavity. I then leveled off the area and set the j-bolt into the concrete, and then set the sill plate over the area to make sure the bolt was in the correct location.
This is what happens when you dont wear boots in a construction area!
There will be an outer ring of grow beds around the perimeter of the dome, and also a central ring. This 2 inch drain pipe will allow the beds to drain into the central sump tank. The piping is temporarily set on bricks to make sure they are sloped in the right direction.
More dirt is filled between the pipe areas and sand is filled around the pipes. This helps to protect them from stone and allows them to be fine-tuned for the proper slope.
Now that all the drain pipes are installed, the sump tank can be dropped into the well. Holes are cut through the side of the tank and the pipes are pushed through the holes. I plan on installing an elbow at the end of each drain to try and swirl the water a bit.
The large sump tank is a bit trickier to install since the cone shape needs to be properly supported. I made a quick template that was equal to the angle of the cone. Sand was then added to the bottom of the well and I used the template as a guide to shape the sand into the same angle as the cone. The tank dropped into place perfectly!
The dome will sit on a 16 inch knee wall. Although each section should match perfectly with the dome, they will be left loose until the dome is assembled so they can be adjusted. Each section is placed on a strip of foam to help prevent air from leaking between the concrete wall and the boards. They are then loosely bolted into place.
Thats it for now. Thanks for watching and dont forget to join our Facebook page at the link below.
Ive made some excellent progress in the last month on the dome! The entire concrete block wall was built and Im now moving on to some of the heating and plumbing that will be buried under the floor. Im still hoping to have most of it built before the snow flies!